MATS WILANDER, 7-TIME GRAND SLAM CHAMPION: I can see her win at least another six, seven meetings (ph).

CASH: Serena Williams has never dominated the game quite like this -- Wimbledon champion, Olympic singles and doubles Gold Medallist, U.S. Open champion and the commanding performance at the season ending WTA Championships in Istanbul, which she won without dropping a single set.

UNIDENTIFIED MALE: There she is, Serena Williams.

CASH (on camera): Do you know how good you are?

SERENA WILLIAMS, 15-TIME GRAND SLAM CHAMPION: No. I don't look at it that way. I feel like I'm just like everyone else.

CASH: Serena.

S. WILLIAMS: No, really. I don't look at me being great or me being good. I just -- I'm a player and I know I'm good at tennis. And I get nervous. I get -- I get apprehensive. I have all those feelings.

And...

CASH: But you hide them then, on the court.

S. WILLIAMS: I do. I'm a good actress. But I have all those emotions and feelings, which I think is completely normal. And then sometimes I think really what helps me is I'm really strong mentally. It helps me get through.

CASH (voice-over): Mentally strong, physically strong and a killer serve that leaves her opponents with nowhere to turn.

ALLASTER: I think it's just starting to sink in that she truly is one of the best players of all time.

JOHN MCENROE, 7-TIME GRAND SLAM CHAMPION: To me, overall, when Serena is on, she's the best I've ever seen play. But the whole package, as far as what she can bring to the table.

CASH: Serena's 15 grand slam titles have earned her a seat at that table where the name cards read Chrissie (ph), Martina and Steffi.

S. WILLIAMS: Actually, I've played Steffi. But watching her is really cool and all that she did with tennis and winning so much and being such a champion. And, you know, to have me being that little girl from Compton, mentioning my name with Martina Navratilova and Steffi Graf, I'm like, me?

Like I'm just having fun.

CASH: That little girl from Compton grew into a tennis sensation, setting precedents and meeting presidents along the way.

But two years ago, she suffered a series of setbacks which kept her off court for almost a year.

First, treading on broken glass, leaving her on crutches. And then, life-saving surgery to remove a blood clot on her lung.

The road to recovery was patchy. By the end of May this year, Serena's comeback had met with early exits at both the Austrian and the French Open.

S. WILLIAMS: For me to lose in Paris was completely disappointing. I was completely shattered. I was really sad. I didn't leave my house for two days. And I was really disappointed and...

CASH (on camera): Did you watch the tape?

Did you watch movies?

S. WILLIAMS: No...

CASH: Did you...

S. WILLIAMS: -- I just...

CASH: -- try to get out of it?

What did you do?

S. WILLIAMS: I don't know. I never do that -- I'm -- I was just in a bad place. And it just -- the place got smaller and it got darker and worse and worse. And I had to eventually let that go. And once I was able to do that, I was able to do better.

CASH (voice-over): And Serena did do better -- a lot better -- winning 31 singles matches with just one loss in the second half of the season.

(on camera): I -- I was there when you won Wimbledon. And, Serena, I -- I don't think that I've ever seen a player more happy to have that trophy...

S. WILLIAMS: Yes, I was really excited...

CASH: -- and posing...

S. WILLIAMS: -- and I'm jumping and, yes. No, I was really happy because even when I lost the second set, I panicked. And then after that, I thought, I'm never going to win another grand slam. I'm going to be stuck at 13 for the rest of my life. And, you know, I should have been happy the last time I won Wimbledon.

And then, when I was in the hospital I thought I wouldn't even play tennis again.

CASH: Of course.

S. WILLIAMS: So to have that opportunity from going from that low, from the bottom to the top, it was -- for me, it was probably the highlight of my year.

CASH (voice-over): Another highlight of Serena's year was to be found far away from the grand slam circuit. It was an experience she shared with her sister Venus.

The pair traveled to Nigeria and South Africa to inspire local girls to fulfill their potential. UNIDENTIFIED FEMALE: So I'm very happy they are coming here to be -- to tell us how they made it, to make us to look like them, to be like them.

S. WILLIAMS: My role model has always been my sisters. I grew up really close to all -- all my sisters, so I really looked -- I really looked up to them.

CASH: The Williams sisters' popularity in Nigeria brought traffic to a standstill wherever they went, as they took time to hold a tennis clinic in Lagos, with children aspiring to follow in their footsteps. And when it came to an exhibition match between the sisters, one spectator clearly had aspirations of his own. Although they were on opposite sides of the net on this occasion, the Williams sisters have supported each other throughout the ups and downs of their careers.

VENUS WILLIAMS: For me to get a win, and Serena, it means 2013 is going to be a great year for me.

S. WILLIAMS: Well, we're really close in age, even though we're not twins. We're 15 months apart. So everything that she's done, she's done so much for me. I mean I think one of the hardest jobs in the world is to be an older sister. And I think Venus is an amazing older sister she was a great role model for me. And we feel each other. Like I -- I can talk to her. She knows exactly how I feel about so many different issues and I love it. I love having that relationship.

CASH (on camera): We spoke with -- with Venus, shortly after you won your -- your gold medal. I just wanted to read out something very quickly she said after that. "I wanted her to win so bad, you don't understand. I was -- and I was just amazed by her performance."..

V. WILLIAMS: -- amazed by her performance. And she never let go. And, you know, in these matches, you can't give an inch or it can turn around quickly. So I was amazed at how strong she stayed. And for her win -- for her, winning, is the same thing as me winning -- if she doesn't win, then I'm devastated, as well. So when she won that gold, it was like me winning, as well.

CASH: You winning as well?

V. WILLIAMS: Yes.

S. WILLIAMS: I feel the same way when she doesn't win. I can't even watch. So, yes, like when she wins, I win. I feel the same way. And when she loses, oh, I lose. I feel that loss.

CASH: I've heard some rumors about Rio.

UNIDENTIFIED FEMALE: Um-hmm.

S. WILLIAMS: Those rumors are true. I don't usually confirm rumors, but I'm here to confirm that those rumors are true.

CASH: Another four years of Serena and Venus?

S. WILLIAMS: Another four years, yes. Absolutely. I mean we love the Olympics. So for us it's like we hope to be there. We're hopeful.

CASH: Would you play every year on tour still for another four years?

S. WILLIAMS: I would.

Why not?

What else am I doing?

CASH: And Venus said she'd do it, as well?

She said that...

S. WILLIAMS: Yes. There -- we -- we love it, you know?

We -- we've had -- we've built our careers to last a long time and we want to be there.

(END VIDEO TAPE)

CASH: So if you were facing her on the other side of the net, how do you solve a problem like Serena?

We asked the top players in the world to reveal their secrets.

(BEGIN VIDEOTAPE)

AGA RADWANSKA, WORLD NUMBER 4: I think it's really hard to say anything about her strategy. She's just -- when she has her day, it's just, you know, too tough.

SARA ERRANI, WORLD NUMBER 8: It's very difficult, because when she serves better than you, (INAUDIBLE) better than you, it's difficult.

PETRA KVITOVA, WORLD NUMBER 8:

She's very strong. She's very smart. She knows what she has to play in the right moment. And she has a big serve.

VICTORIA AZARENKA, WORLD NUMBER 1: I feel it's a great challenge and a great opportunity for me to -- to be a part of. And, you know, obviously, I want to beat her.

ANGELIQUE KERBER, WORLD NUMBER 5: It's very difficult to beat her. And you need to play, really, 100 percent and give your best you can. Then you maybe have a chance to beat her.

KVITOVA: I have always a game plan for every opponent. So it's the same against Serena.

AZARENKA: (INAUDIBLE) tough. I only beat her once.

(END VIDEO TAPE)

CASH: Well, there's no doubt Serena is an incredible player and is still winning. It doesn't look like she's slowing down at all.

(voice-over): Still to come on OPEN COURT, a parade of sharp dressed men -- the players on tour hit the red carpet in London.

(COMMERCIAL BREAK)

CASH: Welcome back to OPEN COURT.

London rolled out the red carpet for tennis royalty for the ATP World Tour Finals. The top players were dressed for success at a glitzy charity gala to kick off the season-ending tournament.

NOVAK DJOKOVIC, WORLD NUMBER 1: Four grand slam winners in a single season, which is, I think, remarkable for our sport after many, many years. And, well, a season finale could not be held at a better moment for -- for tennis.

ROGER FEDERER, WORLD NUMBER 2: Unfortunately, I'm not going to be world number 1 at the end of the year, but Djokovic had a -- a tremendous season. He deserves it totally, because I truly believe world number 1, it's not lucky. You -- you really go -- go out there and have to earn it.

CASH: Novak Djokovic celebrated many great moments this year. He will finish 2012 in the number 1 spot, the second consecutive year.

I have to say that the best tennis players in the world clean up pretty well.

Now, let's get back on court and trade in those striped ties for some tennis kicks (ph).

The spotlight soon shifted from the gala night out to the center court at London's 02 Arena, the venue that's best known for concerts by the likes of Led Zeppelin, Elton John and the Rolling Stones set the stage for Djokovic, Federer and Murray. Only eight invitations are sent to the best singles and doubles teams in the world.

I looked at the singles draw and found it interesting that no Americans or Australians were amongst the group, two nations that host grand slams. Smaller countries such as Switzerland, Serbia and the Czech Republic are changing the global face of the game.

FEDERER: Many of the bigger countries who were very spoiled in the past, who used to have many, many players at the very top of the game are complaining now, why don't we have that many players anymore?

But I think it's because many smaller countries have also produced, actually, many good players.

CASH: I don't think that I ever would have predicted that two Serbian players were amongst the top eight at this tournament.

DJOKOVIC: We are very proud to be the country that has the most representatives on this tournament, you know, in the -- in the singles. Of course, also, Janko (ph) had a great year. And, uh, you know, four our small country that appreciates the sport very much and that -- that also follows the results of their athletes is -- is a -- is a huge thing. It's a very big deal.

CASH: In the end, a Serb lifted the ATP World Tour Finals trophy, a fitting way for the world number 1, Novak Djokovic, to close out the year.

Whenever I attend the ATP World Tour Finals, I'm always anxious to get on court. I've had some great face-offs this year with Pete Sampras, Jim Courier.

Now, you can run me around now.

David Ferrer and Stan Wawrinka. But there are two players that I've been hoping to hit with all season long. Leander Paes and Radek Stepanek teamed up to win the 2012 Australian Open and finished this year as semi- finalists in London.

UNIDENTIFIED MALE: You know, I figure that if we are going to take on the -- 1987, was it?

UNIDENTIFIED MALE: Yes.

UNIDENTIFIED MALE: The 1987 Wimbledon champ, I figured we needed to look the part.

Now, you guys are two of the old established players that I've ever seen. Now, we know you.

(CROSSTALK)

CASH: But you're really old.

UNIDENTIFIED MALE: Thank you very much.

CASH: You're really old.

(CROSSTALK)

CASH: -- just take you on.

UNIDENTIFIED MALE: OK.

You really have that much confidence?

You know, I've got to tell you, Pat, growing up as a kid, I always used to watch your volley, especially your forehand volley. And my coach used to give me so much stick, come on, Lee, get down. You see how Pat volleys. Get down. Use your legs.

CASH: You guys are old school. I mean it's -- Radek, you're still 35 in the world in singles.

How do you manage to do both?

RADEK STEPANEK: I started playing doubles on the tour in 2001, when Lea asked me to play with him. It was an honor to play with such a legend.

CASH: There you go, an easy one to start with. Oh. Oh.

Geez, you got it back, almost.

Twenty seconds between points, right?

UNIDENTIFIED MALE: OK.

UNIDENTIFIED MALE: Twenty or 25?

PAES: I'll take 25, all right.

CASH: What's the secret of a good doubles team?

PAES: To have a great partner and just says "yours" all the time.

(LAUGHTER)

STEPANEK: I think the chemistry between the partners must be...

PAES: Yes.

STEPANEK: -- must -- must be high and they have to get along well.

PAES: Coming at you.

CASH: People ask me who my favorite tennis player to watch. Roger Federer is sort of equal number 1 to you.

STEPANEK: You know, I -- I stayed with my game since I was a kid. I was an (INAUDIBLE) changing (INAUDIBLE) coming (INAUDIBLE). You guys did the past generations.

CASH: Thanks, guys and good luck to you.

(CROSSTALK)

CASH: Good luck in the cue (ph).

(END VIDEO TAPE)

CASH: And still to come on OPEN COURT, the top ladies of the game as you've never seen them before.

(BEGIN VIDEOTAPE)

PINTO: If you don't want to answer something, you can use one pass.

KVITOVA: One pass?

PINTO: One pass.

KVITOVA: How many questions?

(LAUGHTER)

PINTO: That's for me to know and for you to find out.

(END VIDEO TAPE)

(COMMERCIAL BREAK)

CASH: Seven highly successful women from seven different countries -- they're the best in the business when it comes to tennis.

But how do they match up to our top interrogator, Pedro Pinto, in a quick fire arena?

It's time to find out.

(BEGIN VIDEOTAPE)

PINTO: What's your favorite movie?

AZARENKA: I'm not going to say what it is.

PINTO: Toughest player to compete with in your whole career?

MARIA SHARAPOVA, WORLD NUMBER 2: Monica Seles.

PINTO: Whoa.

SHARAPOVA: I played against Monica a couple of times in the beginning of my career and got spanked (ph).

PINTO: Yes.

What's the favorite thing about your home country?

KERBER: That you can drive very fast on the highway. That's the favorite thing.

RADWANSKA: My cousin Bob (ph).

PINTO: Complete this sentence for me, please. "If I wasn't a tennis player, I would be."..

RADWANSKA: For sure, not a singer, because I can't sing. But any other...

(CROSSTALK)

RADWANSKA: -- so I don't know.

PINTO: The favorite thing about your home country.

ERRANI: Eating good.

(LAUGHTER)

ERRANI: Everything is about eating.

PINTO: What's your favorite actor?

LI NA, WORLD NUMBER 7: Grio (ph).

PINTO: That's his name?

NA: Yes.

PINTO: OK. I couldn't say that.

So these are fun questions. You can be very short with your answers if you want. If you don't want to answer something, you can use one pass, all right?

KVITOVA: One pass?

PINTO: One pass.

KVITOVA: How many questions?

(LAUGHTER)

PINTO: That's for me to know and for you to find out.

What's your best shot?

RADWANSKA: My best shot?

I think jump shot.

ERRANI: Backhand.

SHARAPOVA: I like my swinging volley.

ERRANI: But I like more to play fun.

KVITOVA: Serve.

PINTO: OK.

KVITOVA: And forehead sometimes.

PINTO: The greatest player of all time?

AZARENKA: For me, always (INAUDIBLE) Steffi Graf.

RADWANSKA: Steffi Graf.

SHARAPOVA: Steffi Graf.

ERRANI: Serena.

PINTO: Food you miss most when you're on the road traveling?

RADWANSKA: I miss Polish food. I love Polish food, so, yes.

NA: Rice.

RADWANSKA: Especially Polish soups are so good.

ERRANI: Good pasta.

PINTO: Tough to find?

ERRANI: Yes, very tough.

RADWANSKA: Dumplings.

NA: I -- I really have to eat rice, otherwise I'll feeling -- I'll lose all the energy.

PINTO: Favorite actor?

ERRANI: Denzel Washington.

RADWANSKA: Matt Damon.

AZARENKA: I like (INAUDIBLE) Johnny Depp.

KVITOVA: George Clooney.

SHARAPOVA: Jack Nicholson.

PINTO: Old school.

SHARAPOVA: Old school.

PINTO: Complete this sentence for me, please.

"If I wasn't a tennis player, I would be."..

ERRANI: A basketball player.

PINTO: Yes?

ERRANI: I love basketball.

PINTO: What...

ERRANI: But I'm not so tall.

PINTO: Well...

ERRANI: Maybe with one meter more. But I love it.

PINTO: Favorite actress.

SHARAPOVA: Julia Roberts.

KVITOVA: Julia Roberts.

AZARENKA: Julia Roberts.

ERRANI: Julia Roberts.

PINTO: Or favorite movie.

NA: "Sex in the City."

Can I say that?

PINTO: Yes.

SHARAPOVA: "Something's Gotta Give."

ERRANI: "Matrimoni de (INAUDIBLE)." That's not my English.

PINTO: "The Wedding of My Best Friend."

ERRANI: Yes, Julia Roberts.

PINTO: "My Best Friend's Wedding."

ERRANI: Julia Roberts. I know it word by word.

PINTO: Yes?

ERRANI: Yes.

PINTO: Really?

ERRANI: Yes.

PINTO: How many times have you which had it?

ERRANI: One hundred.

PINTO: Wow!

So in the First World War, what was the date -- no, I'm joking.

KVITOVA: Ha.

Toughest player to compete against you during your career?

RADWANSKA: Serena.

AZARENKA: Serena.

KVITOVA: Serena in Wimbledon.

ERRANI: Serena is so strong.

NA: Serena.

PINTO: That's quite a popular answer.

NA: I try as hard as I can, but never, never going. No.

PINTO: Well, don't give up.

NA: OK, I will -- I will try again.

(END VIDEO TAPE)

CASH: Be sure to check out our Web site for more on Serena Williams and her remarkable year.

Next month, we travel to the Czech Republic, where Lucy Safarova Petra Kvitova and Tomas Berdych have re-energized a tennis hungry nation.